Machine for generating curved surfaces



July 31, 1945. w. J. JOYCE ET AL I 2,330,445

MACHINE FOR GENERATING CURVED SURFACES Filed May 21, 1945 2 Shets-Sheet1 l3 INVENTOR WILLIAM JOYCE dACKSON 4*; 4 BY GEORGE July 31, 1945. w JJOYCE AL 2,380,446.

MACHINE FOR GENERATING CURVED SURFACES Filed May 21, 1943 2 Sheets-Sheet2 IN VEN TOR WILLIAM J. JOYCE BY GEORGE W JACg'SON ZTTORNEY PatentedJuly 31, 1945 UNITED STATES. PATENT OFFICE I zssosss Company, 1 Hana, avoluntary association of Ma-achasetts Application May 21, ms. semi No.mm

5 Claims. (01. 00-24) This invention relates to curve generating devicesand has particular reference to an auxiliary attachment adapted for usewith standard curve generating devices commonly known in the art as laptruing machines. for producing tools for generating curved surfaces onlenses and method of making the same.

The principal object of the invention is to provide an auxiliaryattachment for lap truing machines adapted particularly to increase thecurve generating range of such machines whereby surfaces of relativelylong radii of curvatures beyond the range obtainable by'the inherent laptruing machines maybe obtained.

Another object of the invention is to provide an auxiliary attachmentfor standard lap truing machines which may be quickly and easilysupported in operative position without altering the general initialoperating characteristics of the lap truing machine.

Another object is to provide an auxiliary attachment readily attachableto a standard lap truing machine whereby the powerv generating parts ofsaid machine are utilized to obtain the operative function 01' saidauxiliary attachment.

Other objects and advantages of the invention will become apparent fromthe following description taken in connection with the accompanyingdrawings and it will be apparent that many changes may be made in thedetails of construction, arrangement of parts and methods shown surfacecurvatures which they were capable of producing with the limitationsbeing primarily in weak orshallow curve generations,suchcurvesbeingcommonlyknownasthosehavingarelatively long radius of curvature. Thereason for suchlimitationwasthatmachinesofthisnatureareusedbylensdlspenserswhmin most instances, do business in oflicebuildingswhicharelimltedinarearequiringsuchmachinestcberestrictedastosise.'Withoutthis limitation it would be possible to produce substantiallyall of the curve generations required.Inthepast,whenshallowcurvedlapswererequired, such laps were inmostinstances obtained from optical manufacturers who have the facilitiesfor producing them. 'Zfliiswas withaviewtoenablingthecommereiallaptmingmachinestobepracticalforsmailsbopuse'Althoughthe prior rt lap machines did notproduce the full range of curvaturesoflaps requiredthey did produce someof the most essential cums generations. This, however, has been adecided handicaptolens dispcnsersastimehasbeenlostinthepastinhavingtosendtotho factory for shallow curve laps whensuch laps were required.

and described-without departing from the spirit of theinvention asexpressed in the accompanying claims. We, therefore. do not wish to belimited to the exact details of construction, arrangement of parts andmethods shown and described as the preferred forms only have been givenby way of illustration.

Referring to the drawings:

Fig. 1 is a perspective view of a standard lap truing machine showingthe auxiliary attachment of the'invention in operative position.

Fig. 2 is a plan view of the device illustrated in Fla. 1;

Fig. 3 is a fragmentary side elevation of said device; and V Fig.iisafragmentaryenlargedsectionalview takeglasonlineL-loflrig.8.

Machines to which the device embodying the invention are applied arecommonly known i the art as lap truing machines which are capabli ofgenerating diiferent surface curvatures on laps used in forming curvedsurfaces on lenses. laptruingmachinesofthisnatureinthepsst. havebsenlimited astothenumber-of diifercnt The present invention, therefore, isadapted particularly to overcome this difliculty through the provisionof an auxiliary attachment through which the required shallow curvegenerations could be obtained particularly without requiring redesigningof the commercial lap truing machines already in use.

Referring more particularly to the drawings wherein like characters ofreference designate like parts throughout the several views, in thefigures there is illustrated one of the commonly known commercial laptruing machines. This lap truing machine comprises a base 8 havingSpaced uprights I and I in which is pivotally supported. as illustratedat I and}, ayoke ll having a centrally located bearing ll thereon ineccentric relation with a line extending through the spaced bearings 8and 0. The base I is provided with a slideway I! in which a slide plateIt is mounted. ThisisbestshowninFlgJ. Theplate it is provided with acentral hearing it in which the pivot projection ll of a plate member I.is rotatably supported. The plate member ll is, in turn, provided with aslideway ll to which a slide plate It is slidably connected. The slideplate II has the base" of an upright 2| pivotally secured thereto by asuitablv pivot member II. The plate member ltisproviued withaworm scarsector I! meshing with a worm gear 28.

of. The bearing 21 is adapted to support a lap,

which is to be surfaced. The bearing i I, in conventional use. isadapted to support the cutting tool for engaging the lap 28 when theyoke iliis reciprocated about its pivots 8 and 9. This causes thecutting tool to move in vertical strokes transversely of the face of thelap 28 and such motion is imparted to the yoke through a power drivendisc 29 having a connecting rod eccentrically pivoted thereto asillustrated at 3|. The connecting rod 30 is connected with motiontransfer lever means to the yoke iii which through rota tion of the disc29 and the eccentric pivot 8! will cause the connecting rod 30 tooperate said motion transfer .lever means 32 and cause the yoke iii tohe reciprocated about its pivot members 8 and 9. The extent of saidreciprocal movement is sufilcient to cause the cutting tool to traversethe entire width of the face of thelap 2B which is to be machined.Simultaneous to this function a power driven adjustable stroke awl 23 ena es the ratchet wheel 25 and advances said ratchet wheel an amountequal to the tooth dis lacement of the pawl. A suitable sprin ressedplunger 3| havin an en a ement ortion with teeth of th ratchet wheel isadapted to hold said ratchet wheel in advanced nosition. 'his causestheratchet wheel 25 to rotate and to. in turn. rotate the worm gear 23. Theworm ear 22 which is in rneshed relation with the ear sector 22 willcause the support 20 to be swung in an are about the pivotal member I.The above causes the lap to move in a direction substantially normal tothe path of movement of the reciprocatin cutting tool carried by theyoke in. This is merely eneral escription of a conventional lap truinqmachin During such rotarv movement of the plate is he base I! of theupright 20 is locked in fixed r lation with the slide plate is bv anysuitable means not shown.

It is to be understood that prior to causin he cutting tool to reciprocae tra nsversely of the face of the lap 28 and to simultaneousl cause sailap to move in a ath substan allv normal .to t e a h of movement of hecuttin tool the lap and cuttin tool are initially adiusted relative toeach other. that is. with respect to the center of the.

pivotal supports l5 and Band 9 respectively to.-

ob ain the curve generations desired.

It is also to be understood that thelap SllDnOrt 20 is initiallyadiusted in a sid wise direction an the lap. Again the above is merelydescriptive of a conventional lap truing machine. The length assaue ofthe slidcway ll controls the limit of curvature as to long radius curvegeneration.

The above describes the forming of a concave surface on the lap 22. whenit is desired to generate a convex curvature the lap is supported by thebearing H and the cutting. tool is supported by the bearing 21 causingthe curvature opposite to the direction of the concave curvaturedescribed above to be generated.

The slide plate II is movable longitudinally of the slideway I! by asuitable conventional thread adjustment member 35. The slide member I:is movable longitudinally of the slideway l2 by a I similar conventionaladjustable screw member II operated by'the hand lever 21.

The device embodying the invention, which is the form of auxiliaryattachable parts, comprises an upright member 28 which may be detachablyconnected with the base I by any suitable means, such as bolts 39, asshown in Figs. 2 and 3. The upright 38 is provided with spaced openings40 and II. The opening 40 is adapted to support a bar member 42 having apivot coupling 43 adjacent one end thereof to which a hollow rod-likemember 44 is pivotally attached, as indicated at 45. The hollow rod-likemember has an additional rod-like portion 46 in telescopic'relationtherewith, which additional rod-like member 48 is threadedly connectedwith the base I! of the up-' right 20, as shown at 41 in Fig. 3. Asuitable clamp screw 48 is provided for locking the rod 46 in properadjusted relation with the hollow rod-like member 44, and a suitableclamp screw 82 looks the bar-like member 42 in the opening or'bearingII.- It is to be, noted that the axis of the pivot is disposedsubstantiallyin a vertical direction so as to permit sidewise movementof the base it carry-' ing theuprlght 2U.

The-opening II is adapted to receive an adjustable bar member 49 havinga bracket -mem,- ber 50 pivotally attached thereto as illustrated at 5].The said bracket member is provided with spaced bearing members I2intowhich spaced rod-like members 52 extend and which are locked thereinby suitable set screws or the like to a bracket member 58, having a toolcarrying head or holder 51 formed integrally therewith and in which asuitable cutting tool or the like 58 is secured. The head or holder 57is so formed as to permit the attachment of the lap 22 thereto insteadof the tool 58 if desired. The bracket member 56 has a driving link l9pivoted thereto as illustrated at 60. The said driving link is, in turn,pivotally connected to a bar memberv GI as illustrated at 62. The barmember BI is adapted to extend within and to be secured in the hearing Hof the yoke II.

With the auxiliary attachment, such as set forth above, the feed screwmeans 35 is disassociated with the slide ll so as to permit said slideit to be moved freely longitudinally'of the slideway II. The base i9 isdisconnected from the plate l8 so as to permit free pivotal movement ofthe base It relative to the pivot 2|.

Power is then applied to rotate .the disc 29 and" to operate the drivepawl 22. As the disc 29 rotates, the connecting rod 30 through themotion transfer lever means 32, imparts an up and down reciprocatingmovement to the yoke II. This movement is transferred through the linkall of the objects and advantages of the inven- 89 to the bracket" andcauses the cutting tool 58 to reciprocate in a vertical direction aboutthe center as the center of rotation. This causes the tool to move aboutan arc whose radius of curvature is equivalent to the distance betweenthe center of the pivot BI and the point of the cutting tool 88.Simultaneous to this up and down movement of the tool the upright 20,

carried by the base l8, and which is threadedly connected with thetelescoping rod-like members 48 and 44 respectively, will be caused tomove in a sidewise direction about an arc swinging'about the pivot 45 asthe center of rotation. This causes the lap 28 to move in said are andthe radius of curvature generated along the horizontal meridian of thelap 28 will be equivalent to the distance between the center I and thepoint of the cutting tool measured along a line parallel with the axisof the rod-like members 44 and 46 and intersecting a plane parallel tothat line and touching the point of the cutting tool. This arcuatemovement is imparted to the lap 28 through the combined sliding movementof the plate l8 on the slideway l1 and the pivotal movement on the baseis relative to the plate l8,

It is to be understood that the radius of curvature generated along thevertical meridian by the-stroke of the cutting tool may be varied byloosening the set screws 54 and 55 and by adjusting the bar member 49inwardly 'of the hearing 4i and simultaneously causing the bearing 52 tobe adjusted inwardly longitudinally of the spaced rod-like members 53.When the required radius of curvature is obtained the respective setscrews 54 and 55 are moved to locking position. Independently of thisadjustment. the curvature generated in the horizontal meridian throughthe horizontal movement of the lap may be controlled by loosening theset screws 48 and 63 respectively whereby the hollow rodlike member 44is moved inwardly longitudinally of the rod-like portion 46 which, inturn, simultaneously moves the bar portion 42 inwardly of the opening orbearing 40. When the proper radius of curvature is obtained therespective set screws 48 and 63 are moved into proper adjusted position.Suitable gauge means may be provided for obtaining accurate adjustmentsas is conventionally employed and commonly known in the art. The barmember 6| is secured in adjusted position in the bearing II by asuitable set screw or the like 64.

Prior to starting the cutting operation it is to be understood that byoperation of the hand lever 26 the lap 28 may be moved sidewise anamount sufficient to clear the tool which, when the cutting operation isstarted, the said cutting tool will traverse the entire face of the lap28. This is a conventional adjustment commonly known in the art.

'Iheabove describes the method of formingconcave laps 28. When it isdesired to form convex laps the cutting tool 58 is supported by thebearing 21 and the lap 28 is supported by the head 57.

With the above arrangement, it is possible to generate surfacecurvatures of a considerably longer radius of curvature than is possiblewith the initial conventional curve generating machine and thistherefore greatly increases the obtainable range of curvatures.

From the foregoing description it will be seen that simple, eflicientand economical means and methods have been provided for accomplishingmachine having means formoving a work sup-- port and a tool support insubstantially perpendicularly related directions of movement, saiddevice comprising a bracket attachable to the machine and having spacedbearings therein, means adjustably supported in said bearings, arod-like member pivotally connected to one of the means adjustablysupported in said bearings and having means for attachment to one of thesupports of the machine for causing said support to move in a path aboutthe center of the pivot of said rod-like member, a second rodlike memberpivotally connected to the other of said adjustabl means in saidbearings and having means for attachment to the other of said supportsof the curve generating machine for causing said support to move aboutthe center of the pivot of said latter rod-like member when th saidsupports are moved in said perpendicularly related directions.

2. A device for use with a curve generating machine having means formoving a work support and a tool support in controlled directions, saiddevice comprising a bracket having means for attachment to the machineand having spaced bearings therein, a bar-like portion adjustablymounted in each of said bearings, each having a pivotal connectionadjacent one end thereof, a plurality of rod-like members,

one pivotally connected to each of the bar-like portions, one of saidrod-lik members having telescoping portions, means for securing saidtelescoping portions in fixed relation with each other, one of saidrod-like members having means for attachment with one of the supports ofthe curve generating machine and the other of said rod-like membershaving a holder por tion adjacent the end thereof opposed to its pivotalconnection with its respective bar-like portion and link meansconnecting said holder portion with the other of said supports of thecurve generating machine.

3. A devic for use with a curve generating machine having means formoving a work support'and a tool support in substantiallyperpendicularly related directions, said device embodying a detachablebracket having spaced bearings therein, means adiustably carried by saidspaced bearings having pivotal means adjacent one end thereof, rod-likemembers pivotally connected with each of the respective pivotal means,one of said rod-like members being detachably connected adjacent itsopposed end with one of the supports of the machine for controlling thepath of movement of said support in its direction of movement and theother of said rod-like members having a holder portion thereon, meansadjustably suprality of rod-like members having pivotal connectionsadjacent one end thereof to said means adjustably supported in saidbearings, one of said rod-like members being attached to the worksupport and another of said rod-like members being attached to the toolsupport and means for moving said work and tool supports relative toeach other in said substantially perpendicularly related paths ofmovement.

5. A device of the character described comprising a work support and atool support movable in perpendicularly related directions, a brackethaving spaced bearings therein, a barlike portion adlustably supportedin each of said bearings and having a pivotal connection adjacent oneend thereof, a rod-like member pivotally connected with each oi thebar-like wnLmM J. JOYCE; GEORGE w. JACKSON.

